System of indirect lighting of all spaces



M31111! 1933- J. T. DOURGNON 1,900,436

SYSTEM OF INDIRECT LIGHTING OF ALL SPACES Filed April 18, 1929 2 Sheets-Sheet 1 March 7, 1933. J pou o 1,900,436

SYSTEI OF INDIRECT LrIGHTING OF ALL SPACES Filed April 18, 1929 2 Sheets-Sheet 2 Patented Mar. 7, 1933 UNITED STATES JEAN TIGRANE DOURGNON, OI PARIS, FRANCE SYSTEM OF INDIRECT LIGHTING OF ALL SPACES Application filed April 18, 1929, Serial No. 356,150, and in France April 25, 1928.

This invention has for its object to provide a system of indirect lighting of all kind of rooms, premises and the like, provided with a difl'using surface constituted either by the ceiling or by any other surface such as a wall or a specially provided panel or the like.

The system according to this invention, comprises the combination of luminous sources joined to the diffusing surface, for

example a ceiling or the like, in an appropriate number so as to prevent the formation of shadows upon the surface and due to the irregularities of the same, with one or several optical reflecting or refracting systems.

This system directs the luminous rays emitted by the lamps in planes parallel to each other so that the rays impinge upon the diffusing surface, in combination with directing devices preventing glare and adapted to articipate in the decoration of the place to lighted, in order to direct the totality of the luminous flux emitted by the light-sources upon the diffusing surface which reflects this flux anew into the place to be lighted.

The annexed drawings represent diagrammatically examples of installations effected according to the invention.

Fig. 1 represents diagrammatically a vertical section through a ceiling and a corre-' sponding luminous source;

Fig. 2 is a dia ammatic horizontal section, on alarger sea e, showing the arrangement of a luminous source and of corresponding anti-glaring screens for a luminous source in a corner;

Fig. 3 is a diagrammatic perspective view showing the arrangement of luminous sources and screens according to Fig. 2 in the corner of a ceiling;

Figs. 4 to 8 are diagrammatic plane views showing the arrangement of the luminous sources according to the invention around a ceiling;

Fig. 9 is a perspective view of screens extending along the walls;

Figs. 10 to 14 illustrate a few examples of optical reflecting and refracting systems which can be used in the present invention; 56 Fig. 15 shows in a vertical diagrammatic section an arrangement for indirect lighting of the walls.

1 Iy improved lighting apparatus is formed, as shown in Fig. 1, bya lamp 1 which may be an electric lamp, a gas-burner or any other kind of lamp of appropriate design and suitable power, mounted in a support 2 suitably fixed to the corresponding vertical wall 3. The lamp 1 is preferably provided with a spherical mirror 4 placed close to the wall 60 and is preferably mounted in such manner that it can be displaced along its vertical axis for adjustment, as may be required, as by a screw 2a.

In front of the lamp 1 is disposed an appropriate optical system or lens 5 of such kind as to direct the luminous ra s emitted by the lamp 1 as well as those emitted by or reflected by the mirror 4 in planes parallel or nearly parallel to one another and in such manner that they impinge upon the ceiling 6 as clearly shown in Fig. 1, so as to obtain a reflection by the ceiling of the luminous rays striking thereon.

Inthe example shown the refracting optical system, 5 is formed by a portion of a toric lens engendered by the rotationaround the vertical axis H containin the lumi nous source, and having a steppe section of a known kind. a

After installation of the apparatus it will suflice to direct the luminous rays toward the ceilin 6 by the inclination of the apparatus in suc manner that the last rays R are directed to a point 3! nearest to the line of in: tersection of the ceiling 6 and the wall 6' opposite to the apparatus.

This regulation is effected by any suitable means by lowering the lamp and its filament upon the axis w-m. Practically this regulation is eifected by the observation of the up per part of the walls receiving the luminous bundle R. The apparatus is adjusted in such manner that substantially no direct li ht is thrown upon the walls and. that the di using surface is lighted as uniformly as possible.

In order to avoid shadows occasioned by irregularities of the ceiling and by the granulations incident to the painting or coating of the ceiling, it is advisable to place the mo \toward the ceiling. These stituted by lamels of suitable mater al, opaque or translucid (ground glass, opalmc be made visible because from their luminous sources constituted by lamps such as 1, in suitable gpposite directions.

According to, ig. 4 the lamps are, for example, disposed in the four corners of a rectangular ceiling. They could, according to Fig. 5, be disposed in the middle of the borders of the celling. But whereas according to Fig. 4 the optical system 5 of each lamp is in the shape of a quarter of the circumference, these optical systems assume for the arrangement according to Fig. 5 the shape of half of a circle. ig. 6 shows the arrangement for an elliptical ceilingz.

It is possible, as indicated in Fig. taprovide, besides the corner-lights or the lights in the middle of the borders, a central light 7 upon the ceiling,

the optical system of this light presenting the shape of a circle.

The direction of the luminous rays is the same in all vertical planes passing through the vertical axis {0-02 of the optical system, the apparatus producing a luminous beam whose opening is or or 360 according to the position imparted to the apparatus, viz. either in an angle, or along the ceilin or in its middle (in which latter case the mirror is of course useless).

If the optical systems are cut, they could the luminous rays do not move away from their theoretical travelling direction. and there 1s no possibility of diffusion.

If using an optical system which is notvery exact, for example one consisting of moulded glass, certain rays will move away theoretical direction (by the diffusion at ,the surface of the glass or by any other reason) and will result in objectionable glare. To avoid this objection, screens 9 are placed (Figs. 1 and 2) in the proximity of each lamp 1 and outwardly of the optlcal system 5, these screens being parallel between themselves and prefera lg parallel to the central rays of the bundle and being arranged to arrest or to difluse the luminous rays directed downwardly and to throw them szreens are conglass, alabaster and so on), and preferably decorated. The lower face of these screens is preferably frosted or the like, so as to avoid glare.

The said lamels are supported at their extremities in suitably shaped fittings fixed to the corresponding walls. In this way a luminous source for the corners will be ob tained corresponding to Fig. 2.

These screens or lamelscan be shaped in any manner, for example as conical bodies whose axis of revolution w--w passes through the lamp or flat wings as g in Fig. 2, extending along the wall, and so on.

Cwing to the described arrangement an entirely indirect lighting of the space will be acquiring thereby obtained, since the ceiling is illuminated by the greater portion of the flux emitted by the difierent luminous sources, the illuminating fluxes of these sources having, if necessary, I

suitably opposite directions in order to suppress all shadows, the parts of the wall and of the ceiling limited b the optical system 5 being covered with a lack coating or any other absorbing coating.

It is also possible to utilize the reflection of these parts of the walls for the general li hting of the piece, by coating them with a c ear color.

By suitably coloring the said parts of the walls and of the ceiling, it is possible to obtain, starting at one part by the luminous flux obtained by a single lamp, a luminous non-colored flux directed toward the ceiling by the optical system 5 and by the screens or wings 9, and, at the other part, a colored flux diffused by the walls situated at the rear of each luminous source, the whole apparatus the aspect of a coloured source, whereas the luminous flux emitted by the said source toward the ceiling is not coloured.

The reflecting or refracting optical system 5 utilized in combination with each lamp can be as above specified, either a reflecting or a refracting system or a system resulting from both preceding systems. The Figs. 10 to 14 illustrate certain optical systems applied in the present invention.

In most cases the optical system will be, as in the example (Fig. 1), a surface or volume of revolution around the axis w:v passing through the source 1 and perpendicular to the surface of diffusion.

In case of employment of a reflecting surface, the generatrix can be either a segment of a parabola 11 (Fig. 10) in the case of a corner-apparatus, or in the case of a middle apparatus (Fig. 11), the axis .ee' of the parabola which is more or less inclined with regard to the horizontal line, or any other gcndering parallel rays in each meridia' plane (a int-like source being sup osed) or of a prismatic section, or of any ot er se( tion specially calculated to produce a un' form lighting of the diffusing surface.

In all cases adjusting means are provide as specified above, permittin the displac ment of theoptical source gsupposed as point) from S to S with regard to the opt cal system (Fig. 12) so as to deviate the 1 tical axis a in order to illuminate better the diffusing surface 6'.

Mirrors 4 with spherical surfaces can be added to all these opticalsystems, in order to I recuperate the flux lost otherwise.

The apparatus, and more especially the central a paratus 7,- 8 (Fig. 7) can .be surrounded y glass bodies with vertical flutes whose purpose is:

(a) To suppress the shadows engendered by the fittings situated eventually in front of the apparatus and to increase at the same refractive; device to direct the time the opening of the bundle of rays in the vertical direction;

in a given direction by tion of the flutes.

Finally, instead of obtainin the optical system by the revolution around the vertical axis-:v-:v, it could be obtained by the trans lation, along a rectilinear directrix or the like, of the sections defined above, the directrix being, for example, erpendicular to the bisectrix of the angle 0? the corresponding walls, as in the diagrammatic disposition of It must be understood that by indirect lighting is meant, not only the lighting through the medium of the ceiling acting as a diffusin surface but also, as specified, the lighting t ough-the medium of any other diffusing surface such as vertical walls 6',-as in Fig. 15, or panels specially provided for this purpose.

Accordin to Fig. 15, the walls 6' playwith regard to t e apparatus the role the ceilin 6 in the example of luminous directed b clined with so as to raze the wall 6".

The surfaces illuminated b the razing rays can be either flat orsligh y curved, the uniformity of lighting being thereby susceptible to be still further increased.

What I claim is: v v 1. A system for indirect illumination of a localized space, comprisin a diffusing-surface forming a seconda light source, a primary source of light ad acent said diffusing surface and an optical dioptric, exclusively a judicious disposi- 1g.- 1, the

the optical systems 5 being infrom the primary lightv source exclusively against said diffusing surface at a slight angle to saiddifi'using surface and substantially parallel to one another said optical device being obtained by rotation about an axis substantially normal 'to the said difi'using surface of a lenticular stepped contour, furnishing rays which define cones or segments of cones, whose bases are on the-said surface and whose apices are at the light projector.

(b) To permit an increase of the intensit layed by undle emitted by the lamps 1 and light rays' the. diffusing surfaces, said. means being screens in the form of rotation elements having the same axis as the optical system and 0t er means for absorbingthe rays diffused toward the rear of the luminous source on the waH sections and the bases limited by the optical system. y

3. 'An indirect illumination system as set forth in claim 1, including-means for re lating the lamp along the axis of revolution of the opticalsystem.

4. An indirect illumination system comprising a difl'using surface forming a secondary light source a primarysource of light adjacentsaiddiifusmg surface, means to direct the-light rays from the primary light source against said diffusing surface at a to intercept the luminous rays which do not directly reach the difiusin surfaces, said means being screens in the orm of rotation. I

elements having the same axis as the optical system.

5. An indirect illumination system as set forth in claim 4, including means for regulating the lamp along the axis of revolution of the optical system to modify the characteristic features of the pencil of rays refracted and to permit by said means the use of the same optical system for illuminating the secondary surfaces of entirely different dimensions.

"In witness-whereof I afiix my signature. wo

regard to the vertical direction JEAN TIGRANIE DOURGNON.

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2. An indirect illumination system as set 

